Since the inception of global industrialisation, the growth of steroid oestrogens becomes a matter of emerging serious concern for the rapid population. Steroidal oestrogens are potent endocrine-upsetting chemicals that are excreted naturally by vertebrates (e.g., humans and fish) and can enter natural waters through the discharge of treated and raw sewage. Steroidal oestrogens in plants may enter the food web and become a serious threat to human health. This study evaluated the uptake and accumulation of ethinylestradiol (EE2) and 17?-oestradiol (17?-E2) in lettuce plants (Lactuca sativa) grown under controlled environmental condition over 21 days growth period. An effective analytical method based on ultrasonic liquid extraction (ULE) for solid samples and solid phase extraction (SPE) for liquid samples with gas chromatography-mass spectrometry (GC/MS) has been developed to determine the steroid estrogens in lettuce plants. The extent of uptake and accumulation was observed in a dose-dependent manner and roots were major organs for oestrogen deposition. Unlike the 17?-E2, EE2 was less accumulated and translocated from root to leaves. For 17?-E2, the distribution in lettuce was primarily to roots after the second week (13%), whereas in leaves it was (10%) over the entire study period. The distribution of EE2 at 2000 ?g L-1 in roots and leaves was very low (3.07% and 0.54%) during the first week and then was highest (12% in roots and 8% in leaves) in last week. Bioaccumulation factor values of 17?-E2 and EE2 in roots were 0.33 and 0.29 at 50 ?g L-1 concentration as maximum values were found at 50 ?g L-1 rather than 500 and 2000 in all observed plant tissues. Similar trend was noticed in roots than leaves for bioconcentration factor as the highest bioconcentration values were observed at 50 ?g L-1 concentration instead of 500 and 2000 ?g L-1 spiked concentration. These findings mainly indicate the potential for uptake and bioaccumulation of oestrogens in lettuce plants. Overall, the oestrogen contents in lettuce were compared to the FAO/WHO recommended toxic level and were found to be higher than the toxic level which is of serious concern to the public health. This analytical procedure may aid in future studies on risks associated with uptake of endocrine-disrupting chemicals in lettuce plants.
Authors: Adeel M, Zain M, Fahad S, Rizwan M, Ameen A, Yi H, Baluch MA, Lee JY, Rui Y. ; Full Source: Environmental Science & Pollution Research International. 2018 Oct 30. doi: 10.1007/s11356-018-3588-4. [Epub ahead of print]